The core serves purposes of general utility and will continue immortalizing cell lines by EB virus transformation from blood samples received from other projects; when necessary, it will provide cytogenetic localization of probes by somatic cell analysis and by "in situ" hybridizations. The computer work related to linkage data will be carried out in the CORE; and new computer programs, the testing by computer simulation of new methods and the statistical support to investigators of the program project, will be mostly done in this group. The new automated instruments now being developed will be operated and maintained by the CORE. Among these is foreseen the acquisition of an automatic thermocycling reactor for PCR (polymerase chain reaction). There is also partial access to an automatic DNA extractor.